The Environmental Pathology Program at the University of California-Davis (UC-Davis), currently entering its 29th year, supports a subspecialty group of veterinary pathology trainees whose research and career interests are in health effects of environmental agents. This program is a part of a larger research Training Program in Pathogenesis of Diseases administered by the Department of Pathology, Microbiology and Immunology (PMI) and the Graduate Group in Comparative Pathology. This is a 6 year overall program leading to American College of Veterinary Pathologists (ACVP) board eligibility and the Ph.D. trainees are supported during their graduate and research program after completing their clinical training in anatomic pathology. Partcipants receive training in comparative pathology, basic cell biology, the cell and molecular basis of disease, and biochemical toxicology and do research activity in faculty laboratories sufficient to qualify for the Ph.D. degree. Training faculty are selected by the applicability of their research program on human environmental health issues. This request is for 3, three year postdoctoral positions which, when combined with students supported by other resources, forms a core of postdoctoral professionals who exists in a self-teaching hierarchy of experience under the mentorship of an interdisciplinary and well funded training faculty. Also requested is one pre-doctoral position to be used for minority recruitment in the DVM Ph.D. program. The foundation of the training program is the established interaction at UC-Davis between the academic discipline of pathology and strong environmentally-orientated research centers, principally in the California Primate Research Center, the Center for Health and Environment, the Departments of PMI, Molecular Biosciences and Anatomy, Physiology and Cell Biology (Veterinary School), Environmental Toxicology (College of Agriculture and Environmental Sciences), and Internal Medicine (School of Medicine). The training uses the format of a specially-tailored Ph.D. degree program in Comparative Pathology. The first 12 months of the 3 to 4-year research program are spent primarily in advanced coursework appropriate to pathology and an introduction to the environmental research programs through seminars and rotations in research laboratories. Trainees next perform a thesis project under the direction of one of the training faculty. Currently active areas include reproductive toxicants, hazards posed by air pollutants and environmental cardiology. BACKGROUND This is a competing continuation application for a training program in Environmental Pathology that has been funded for 29 years. Funds are requested to support 3 postdoctoral positions and one pre-doctoral position. The program is somewhat unique in that the majority of participants have veterinary medical degrees and it provides training in clinical veterinary pathology in addition to research experience as part of the program. At the end of the postdoctoral program trainees are expected to have completed requirements for the Ph.D. degree and are board eligible for ACVP certification. Support is requested for the three-year research portion of the six-year postdoctoral training curriculum. New to this application is the addition of one pre-doctoral training slot within the three-year research portion of the combined Ph.D./D.V.M veterinary scientist training program. The addition of the pre-doctoral slot is requested to facilitate recruitment of trainees from underrepresented minorities. Also new to this application are the addition of components to provide training in presentation skills, literature reviews, increased seminar participation and the availability of new research facilities including microarray and microimaging equipment.